Absigstqb



July 27 1926.

J. wlcxs TELEPHONE SYSTEM Original Filed Ap 1. 1921 a Sheets-Sheet 1Imran mr- Juhn lnficks 4%. Z. W

July 27 1926.

1,593,737 J. WICKS TELEBHONE SYSTEM Original Filed April 1. 1921 JuhnLil/3R5 July 27,19ze. 1,593,731

J. WICKS TELEPHONE SYSTEM Original Filed April 1921 e Sheets-Sheet [40 mmi,

July 27, 1926.

J. WICKS TELEPHONE SYSTEM Original Filed April 1, 1921 John hfmks July27, 1926. I 1,593,731

' J. WICKS TELEPHONE SYSTEM o l Filed April 1. 1921 Juhn Hunks .J. WIQKSTELEPHONE SYSTEM Original Filed April 1, 1921 July 27 9 1926.

6 Sheets-Sheet 6 LU i 1 -InUEnur- Jul-Ln Mmks 54.1

"Patented July 2?,

1 s arts JOHN warm cinema minors s noa e s e nsme r u e- Miirm unscrerim, o c e e m rse' nronermu0 s E A A E rnLnrn'oHE SYsirnrcf I a n atiii fi eri he; i, 1921, Serial No. 451743. Renewed ember s, less.

' The present invention relates in general to telephone systems; but isconcerned more particularly with methods of establishing to" or longdistance com ections automati- "llhe object of the invention may b toconsist broadly in the production of a new and improved toll trunkingsystem hichlong di tance connections are ess, ed automat cally, togetherwith the addition of improved circuits and apparatus whereby suchsystems may be put into efiective operation.

' above indicates in broad terms the sco e of the invention. Variousfeatures incl'u fed in the working of the complete system will not nowbe specifically mentioned, but \vi'llfhe descri'bed in. thespecification which isto follow, and pointed out in the claims.

Of the accompanying drawings to which referencewill be made in thespecification,

' Figs. 1, 2, 3, 1, and'5, when arranged in order with correspondinglines at the ends thereof in alignment, represent diagranr maticallysuflicient off the apparatus used in making a long distance connectionin asys tern embodying the principles of the present invention to enableit to be understood. Fig. 6 is a schematic diagram illustrating tliegeneral'layout of the system; while Fig. 7- shows a cord circuit whichis a modificaion of the one Shown in Fig, 2. 7

Referring to Fig, 6 a manual exchange and two automatic exchanges areshown. which, beginning at the left, will be desig:

-' .nated, respectively, as the No. 1 exchange,

theNo. 2 exchange, and the No. 3 exchange. These exchanges areassuinedto be located in ,diflerent cities and although the exact size is of nogreat consequence they may each have a capacity of 10,000 lines. Gu theassumption that the capacity is as noted above, local connections in theNo. 2 and No. 3 exchanges will be established through themediu n ofindividual line switches or trunk selectors, first sclectors, secondselectors, and connectors. For example, in the No, 2 exchange thesubscriber at substation A is able to establish connection with thesubscriber at substation A through the medium of the individual'lineswitch C, first selector E, second selector F, and the conhector H;ilhis'is the usual percentage trunking systein and is mentioned becauseof the factthat the grenterportiun thereof,

comprising the second selectors and the connector switches, also forms apar\ of a second trunking system used only for the es tablishment oftoll connections. The same is true for the N0. 3 exchange. The No. 1

exchange is a manual exchange and connections are established betweenthe various subscribers, by operators, in the well known manner.

Each exchange is provided with a toll board presided over by one ormore. ope-rators who establish outgoing toll connections. The operatorsin any particular automatic exchange have access to, the localsubscribers lines by way of a first selector and thence by way of'theregular trunking system. Referring again to Fig. 6 thejacik J is oneterminal of a trunk which extends to the first selector Theselector E"in common with the other first selectors such the selector E, hasaccessto theregular second selectors. It is seen thereforethat thelocaltrunking system is' used in completing both toll and local calls.The No. 3 exchange is arranged in substantially the same manner as'theNo. 2 exchange. 1 It is assumed for convenience that the toll operatorsin exchange No. 1 have access to jacks in which thelocal subscriberslines are multipled. Accordingly to complete a connection to a localsubscriber the toll operator plug of a cord circuit 1 and, therefore,connections between these two points must necessarily be extended by wayof the No. 2' exchange, This situation may'arise in'either of two ways.Either or both of the No. 1 and No. 3' exchanges. may

extending be of relatively small size and so located as v o besubsidiary to exchange No. 2. Insuch a case it would be uneconomical toprovide a third group of toll; lines extending directlybetween the No; land the No. 3 exchange. "The second case arises when the exchanges,which may all be of one size, are located in approximately a straightline or where for topographical reasons the toll lines from exchange No.1 to exchange No. 3 pass through or near the city in which exchange No.2 is located. Under these circumstances it has been found most efiicientto cut the through toll lines at the intermediate exchange, therebymaking each section available for short haul messages, and complete allthrough calls by means of switching apparatus at the No. 2 orintermediate exchange.

It will be appreciated now that the toll lines and switching apparatuscomprise a second trunking system and it will be shown in the followingthat this second system is merged into the regular trunking system ateach of the automatic exchanges.

The toll lines terminate at each end in the usual manual drops andjacks. That is, the toll line X extends from jack J in the No. 1exchange to jack J in the No. 2 exchange by way of the repeater D, andthetoll line Z extends from jack J in the No. 2 exchange to the jack Jin the No. 3 exchange by way of repeaters D and D The repeaters D, D andD are associated with the first selectors E, E and E respectively.Considering now the No. 2 or intermediate exchange the banks of all thetoll first selectors includingselectors E and E are connected inmultiple and the first 9 levels, assuming that the usual Strowger typeof switches are used are multipled with the first 9 levels of theregular first selectors as is clearly shown in Fig. 6. Since the tolloperators are never required to call the toll recording operator, who isreached by calling 0, there is thus left available for other purposesthe tenth level of the toll first selectors. This level is used forthrough switching and for this purpose a group of toll second selectorsis provided, one of which is indicated by reference character F. Thesetoll selectors are accessible in common to all the toll first selectorsin the N0. 2 exchange and have common access to all the groups of trunklines terminating in the No. 2 exchange, it being understood of coursethat there maybea number of such groups extending each to a differentcity, in addition to the two groups indicated in Fig. 6. No toll secondselectors are shown in the No. 3 exchange. In case there should be afourth exchange the No. 3 exchange would take on the character of anintermediate exchange and would be equipped in the same manner asexchange No. 2. It is now seen that the same toll first selectors areused for both local toll connections and for through calls from the No.1 to the No. 8 exchange or to any other exchange that may be included inthe systern.

To further illustrate the general trunking system a call may be tracedfrom the substation A in the No. 1 exchange to the substation A inthe-No. 2 exchange. The connection is of course completed by theoperator in the No. 1 exchange and is extended to the called line overthe following path: jack J toll line X, repeater D, toll selector E,second selector F, connector H. The connection, to the local subscriberat substation A, is set up by way of the cord circuit 0 and the jack J.The operator is provided with a jack J subsidiary'to jack J for thepurpose of controlling the automatic switches' The dial cord P isinserted into the dial jack J and the calling device associatedtherewith is turned in the usual manner to make the connection. Assumingnow that the called substation is the substation A in the No. 3 exchangethe connection thereto may be extended over the following path: jack Jtoll line X, repeater D, toll first selector E, toll second selector F,repeater D, toll line Z, repeater D toll first selector E secondselector F and connector H.

It is thought that the foregoing is sufficient to make clear the generallayout of the system. the circuit drawings comprising Figs. 15,inclusive, for a description of the apparatus involved. These drawingsshow diagrammatically all the equipment necessary to establish acomplete long distance connection between the substation A and a trunkline leading to a first selector in the exchange No. 3, it beingunderstood that the connection is completed through the medium of thelocal trunking system to any subscriber in the No. 3 exchange.

The apparatus shown in Fig. 1 is located in the No. 1 exchange; theapparatus shown in Figs. 2, 3, and 1, is located in the No. 2 exchange;while the apparatus shown in Fig. 5 is located in the No. 3 exchange.

Tl e substation is an ordinary manual substation having the usualtalking and signalling instrumentalities and terminates in the manualexchange in an answering ack J which tion. The substations A, A A and Awhich are indicated in Fig. 6 but not shown in detail in the drawingsare of the usual automatic type.

The individual line switches indicated schematically in Fig. 6 may be ofany approved type of trunk selector. Line switches are well known andtherefore will not be described herein. It will be sufiicient to saythat through the medium of line switch C the line of substation A isgiven access to a )lurality of first selector switches, such as theselector E, which form part of the local trunking system previouslydescribed.

Reference will now be had to is located at an A operators posilZO theswitch control 'cir'cur nection' with thesetoll lines is leeway F aremechanicall oi the usual Stroxtger] vertical rotary type of switcheshaving the bank contacts arranged in hori- 'zontal rows o-r' levels. Thecircuits of these "electors are all the same and are shown in detail in3.

The connector switches suchas H and H, shows schematically in Fi "6, aremechani- Cally the same as the selectors; The circuit use d'in theconnectors is a s'iiniJ-le two Wire circuit and is in (10111310111156.

Attention is particularly called to the repeaters among which are therepeaters D, D and if. he circuit of each of these repeaters is soarranged that the regular selector circuit for use in the'lo'caltrunking system need not be changed when the same selector to housedfor, toll connections. The circuits of any two of these repeaters areidentidal and are shown complete and will oedeseiibed fully'llQlllfiITkEL The tollli-nes such as the toll rises X and Z have theusual repeating coils such as the ropes ing coils El, T, T, and T ateach end thereof. The dialing circuit or We might used in conhe well.lrn'oivn siinpleKcircuit; The operation "01" thiscireuit will be pointedout and fully explained hereinafter. o

The tolloperators co'r'd circuits, such as the cord circuit O, 1 inthello. 1 exchange are "arranged with aringing key on :eitlrer end. Theright hand or outgoing end is not, altered but is the same would be usedwere the No. 2 exchange ni'anually operated. The left hand or local eadis identical iyiththe calling end of the ordinary manual o1'3erato'r7s'"cord circuit. The left 114 d 1'4 +15 1 "a" it Q nan o1 OLlLgOlIlg enc()1 Lie COIC eilein 22, in the No.2 exchange 18 the saine as therighthand or outgoing endot the cord circuit Oin the No. 1 exchange, theright hand end of the cord circuit haying the proper circuitarrangements to enable the ,o'p'eretor c'o'ntr'ol'the local switches,and to get answering supervision. Additio'nel cord circuits such as the'one'shor'v n in Fig. '7 they else be provided at the N0. 53 exchange usin establishing direct ina'nual connections between toll lines. The cordcircuits used in the no; veiichang'e are understood to be identical withthose used in the No. "2 exchange.-

'The a p;i'1=atue haying been described in f'ge'n'er'alwill now bedeseiibe'd in connection with af'detailed description of its operation.Forthis purposeit will be assi-in ed that the subscriber at substationA, 1, cle'sires to obtainconnection with a subscriber in'the hereinafterefplain' profi ed method of accomplishing this object will serve, butsince the substation A is e ina'nlial substation it will be assumed thatthe subscriber calls the toll recordingoperator manually and in the wellknown manner which need not he explained. hen the toll recordingoperator answers the callin sul Ecriber es her the desired inferil'ie't'oll re formation on e ticlretor in some other Way, andthen tellsthe callingsubscriber to hang up his receiver. The order is then placedin the hands of the toll operator Whose duty it is to complete 'checonnection.

In the case under consideration the'wani ed subscribers line terminatesin the No. 3 change which must be reached by Way the No. 2 exchange. Thetoll operator, therefore after firstascertaining that the toll line Xexending to the No. 2 exchange is idle, as indicated by the unoperatedcondition of the visual signal 34-,inse'rts the outgoing; plug of anidle cord circuit, the cord circuit O, for example, into the jack.Thereupon the following circuit is completed: from ground by Way of out01f relay 35, the sleeve of jack J corresponding contact on the plug otthe cord circuit O, and relay to battery. The two relays energize inseries but the energization of relay 10 has no eiliect at this time. Cutoii' relay 35 upon energizing, removes at armature the bridge of theupperwinding of relay from the conductors 23 and 2 1, and at armature 37closes a circuit tor the visual signal as. The visual signal 341, aswell as its multiples in frontot the other toll operators in the No. 1exchange s accordingly operated. A branch of this circuitalso e2;- tendsby Way of the resting contact of spring 25 of jack J and said spring tobattery through the repeating relay 2?. Repeating relay 27 uponenergizing. places batery out on the toll line X by way of resistance RCworkingcontact of armature and said armature. conductor J, and the upperand lower right windings of repeating'c'oil The result is; that linerelay 116 of the reneater l), on the other end ofthe trunlr line, in theN0. 2 exchange immediately energizes by Way of the following circuit:fronrground through line relay 116 resting contact of armature 129 andsaid armature. resting contact of armature 119 and said a'rinaturc,

conductor 54, upper and lower left windings of they repeating coil T,trunkline X, and thence byway of previousy traced circuit to battery.Line relay 116, upon energizing, closes at armature 136a circuit for theslow acting release relay 117. Upon energizing. release relay 117grounds the release'trunk conductor 16a of the selector'Efl-asociatedwith the repeater D, fora purpose to he "When We '11 e trunh'eondudplaced "on cording operator records the in said armature.

115 energizes and at armature 135 places ground on release trunkconductor 161 of repeater D to make the said repeater busy to theselectors having access to it. At armatnres 134 and 1 12, the circuitextending to dial jack J is opened so as to prevent any accidentalinsertion of the plug of dial cord P, Fig. 4:, into the said jack fromintertering with the connection. As a further result of the energizationof the line relay 116 the following bridge is closed across trunl:conductors 168 and 165 of selector i l. From trunk conductor 168 bywayof the normally closed contacts controlled by armature 125, resistanceif, working contact of armature 137 of line relay 116 and said armature.and trunlr conductor 165. When this bridge is closed across the trunlrconductors and 165 the line relay 1??) selector E, Fig. 3, is energizedand at i ture 188 operates the release relay 17 6, here by preparing theselector for its usual oper ations.

The toll opera-tor now inserts the plug of the-dial cord P into the dialjack 8 thereby operating the spring 25 of the said jack. The circuit ofrepeating relay 27 is now shifted so as to include the spring 26 of jackJ and the calling device S of the cord P.

The toll operator in the Ho, 1 exchange may now operate her callingdevice in accordance with the first digit of 1c desired nun'iber. Uponreferring to 6 and re HJQD'IbQIlDg' that the connection is to beextended to the N0. 3 exchange, it becomes evident that the first digitcalico must necessarily be 0. W hen the calling device S is operated inaccordance with the first digit 0 of the desired number the circuit ofrepeating relay 27 associated with the dial jack J is broken ten i nesmomentarily. Each time the circuit of the repeating 1e lay is broken it,upon deenergizing, inte rupts the circuit of the line relay 116 of l.repeater D in the No. exchange. 1 line relay 116 of the repeater Drepeats these interruptions at armature 187 to the trunk line comprisingconductors 168 and 16-5 and extending to the selector E, and alsooperates slow relay 118 over the following circuit: from ground by wayof armature 138 and its resting contact, arn ature 188 and its WOYlIiDQ;contact, and slow acting relay 118 to battery. Relay 118 upon energizingcloses at armature 111 a bridge across truni conductors 163 and 165 by amore direct path, excluding resistance so as to obtain a better switchcontrol circuit, and at armature 1 1-0 closes a circuit for relay 112 byway of the resting contact of armature 130 and Jpon energizing, relay112 looks itself to release trunk conductor 164 at armature 127: shifts,at armatures 125 and 128, the original bridge closed across conductors163 and 165 so as to include worlo ing contact of armature 125 and saidarmature, upper right winding of repeating coil T, resistance R restingcontact of armature 1.21 and said armature, lower right winding ofrepeating coil T, and armature 128 and its working contact, instead ofresistance It, and at armature 126 closes the following circuit for thecut off relay 102 associated with jacir J: from ground by way of cut 011relay 102, armature 138 and its resting contact, armature 126 and itsworking contact, and resistance R to battery. Upon energizing, cut oilrelay 102 opens at armature 103 the circuit of the upper winding ofrelay 100, and closes at armature 101 an energizing circuit for visualsignal 106 and its multiples to apprise the operators in the No. 2exchange of the fact that the toll line X is. busy.

In response to the interruptions produced in the bridge acrossconductors 163 and 165 at armature 187 of line relay 116 of repeater D,the line relay 175 of the selector E is deenergized ten timesmomentarily and at each deenergization operates the vertical magnet 180in series with the slow acting relay 177 over the following circuit:from ground by way of the resting contact of armature 192 and saidarmature, armature 183 and its resting contact, armature 185 and itsworking contact, slow acting series relay 177, and vertical magnet 180to battery. By the operation of the vertical magnet the switch shaft andwipers are raised step by step until the wipers stand opposite thetenthlevel of bank contacts. Relay 177 energizes and retains itsarmature attracted throughout the vertical movement of the shaft, andupon the closure of the vertical off normal springs 186, completes acircuit for the stepping relay 178. Upon energizing, relay 178 preparesthe circuit of the rotary magnet 181 at armature 189, and at armature188 establishes a locking circuit for itself in series with the restingcontact of the armature of rotary magnet 181 and said armature. At theend of the vertical movement of the shaft the slow acting relay 177deenergizes and completes the circuit for the rotary magnet 181 whichthereupon energizes to advance the wipers 19%196, inclusive, intoengagement with the first set of bank contacts in the level oppositewhich they are raised. The rotary magnet also attracts its armature andthereby breaks the circuit of the stepping relay 178, whereupon the saidrelay deenergizes and breaks the circuit of the rotary magnet, atarmature 189, which thereupon deenergizes also and again closes thecircuit of the stepping relay.

The operation now depends upon whether the test contact with which thetest wiper 195 is in engagement is busy or idle, If the test contact isbusy there is a ground 139 1 511 tial on it and thesteppingrelay'energizes minating, bank contacts I v sive'. and leading to. thetoll second selec again and the saine cycle of operation is repeatedover and over untilfan idle or ungreunded'test contact is reached. Whenan idlesetot contacts is reached the switching relay 179 energizes inserieswith the step pi-n'g relay 178 over the following circuit:from'ground by way of release trunk conductor 164;, switching relay 179,resting contactof the armature of the rotary magnet 181 and saidarmature, oii normal contacts 186, and stepping relay 17 8 to battery.Re-

lay 178 however, due to its relatively small number of. turns andcomparatively stiff adjustment, does not energize over this circuit; Inthe present case, however, it is assumed. that/the test contact 198 isthe first one found idle. That being the case, the

.energizationoi switching relay 179 switches theconnection through tothe trunk line terlWhen-the connection is thus extended the lin'e andrelease. relays 218 .and 219 in the selector Finnnediately energize andprepare the switch for operation in the usual manner. The toll operatorin the No. 1 ex.- change may now operate her calling device in.accordance with the second digit of the desired number. Referring againto the l ayoutshown in Fig. 6, it becomes evident that the second digitmust be 2 since it is the second level of the selector F that givesaccess to "the trunk line Z leading to the No.

2 eirchange. When the operator. operates her calling device inaccordance w th the digit 2the selector F raises its Wipers 222,

228 and 224 step, by step until they stand 5 opposite the second levelof bank contacts and then rotates thern insearch of an idle t'rii'nkline. I

The operation of the selector F is exactly the same as the operation ofthe sel'e'c'torE" and consequently need not be explained. in detail,Assuming that the trunk line'terniinat ing in bank contacts inclusive,is the first one found idle, the en ergi zaticn of the switching relay23: switches the connectionthrough by Way of the trunk line comprisingconductors 231- 233, inclusi've, to the repeater E.

7 Referring back to the operation of the reeaterD. it will berememberedthat when the release relay 117 energized it placed ergizing,closes at armature the follow-- ing circuit for the'cut oii relay 24:8associated; with the jack J from ground by Way of cut oft relay 248,aneauieiiea's and ductors 231 and including the up er and, lowerwindings of the line relay 258,

air-matures 2&0 and; 2. t1fland ieir"working. contacts, and the upperand" lower left wind ings of the, repeating coil T5 The reentertheclosure of this bridge is that line relay 258 energizes and atarmature 259 places battery out on trunk line Z by way of the followingcircuit: from battery through resistance R armature 259 and its Workingcontact, working contact. of armature 239 andxsaid armaturaconductor260, and the upper andlower right windings of repeating coil T Whenbattery is thus placed on the trunk line Zthe line relay 303 of therepeater D in the Na. 3 exchange is energized over the followingcircuit: from ground by Way of line,relay' 303, resting contact ofarmature 3"02 and said armature, resting contact of armature 801 andsaid arniatu're,fconductor 300, upper and lower left windings ofrepeatingfcoil T trunk line Z, and thence by way of the previouslytraced circuit to battery. It willbe apprecia'ted that, since thecircuit of repeater D exactly the saine as the circuit of repeater D andthat the'repeater D is also connected to'its' associated jack in thesame manner as the repeater D is connected to its associated jack, theresults in this, case are precisely the saine as when the toll operatorin the No. 1

exchange inserts/the calling plug of a cord circuit in the jack J? ofthe trunk line X.

Accordingly the repeater D cl'oses'a bridge across the line conductors304 and 305, and places ground on release trunk conductors 306 and 326'.V

Upon referring to the schematic diagram shown in Fig. 6 it is noted thatthe repeater D isdir'ectly connected to a toll'first se lect-ordesignated by the reference character E Since this selector is exactlythe same as the selectors E and F already shown and described it is notnecessary to show and, describe the circuit of the selector E It willsuffice to say that when the operator again't-urns her calling [devicethat the circuit ofthe upper Winding of theringing response relayassociated with jack J is opened the busy visual associated with thesaid jack is operated, the talking circuit is closed throughto theselector ahead, and the selector E operates to raise its wipers to thedesired level and rotate them to pick out an idle trunk line leading toa second selector such as F, Fig. 6.

When the calling device is turned again the second selector that hasbeen selected operates to give access to a connector switch such as theconnector H also shown in Fig. 6. In responseto the last two digits ofthe called number the connector extends the conection to the desiredline and rings the bell at the called substation. The operator, havingfinished dialling removes the plug of the dial cord P from the dial jackJ after which the repeating relay 27 is maintained energized over itsoriginal energizing circuit.

When the called subscriber hears his bell ringing he removes hisreceiver. He may now converse with the toll operator in the No. 1exchange. his transmitter being su plied with talking current from theconnector that is used to obtain access with his line. Afterascertaining that the desired subscriber has answered, the toll operatortells him to wait while she calls the subscriber that first initiatedthe call. Theremight be any one of several methods used in recallingthis subscriber but as before stated it is assumed in the present casethat the toll operator has in front o1 her a multiple of all the linesterminating in eX change No. 1. That being the case all that isnecessary for her to do is to insert the other plug belonging to thecord circuit 0 into the jack J of the substation A and operate theringing key K. When the subscriber at substation A. answers in responseto the ringing of his bell the toll operator tells him that the calledsubscriber is on the line. The calling and called subscribers may nowconverse with each other, the talking circuit being outlined by heavyconductors as far as the repeater D From thence the circuit is old andwell understood and of course need not be shown.

lVhen the conversation is finished both subscribers hang up theirreceivers. hen the subscriber at substation A replaces his receiver heopens the circuit of the super visory relay associated with supervisorylamp L and thereby lights the said lamp in series with the cut oil relayof jack J. The toll operator upon noting the lighted condition of thesupervisory lamp L knows that the conversation is finished and hencepulls down the connection.

hen the. plug is removed from jack J the circuit of the lamp L is brokenand likewise the circuit of the cut off relay 15. Cut ofi relay 15, upondeenergizing makes the line of substation A ready for another call.

\Vhen the plug is removed from the jack J the circuit of the cut offrelay is broken. Cut off relay 35, upon deenergizing, opens at armature37 the circuit of visual signal 31 and its multiples and also ofrepeating relay 27. Repeating relay 27 upon deenergizing, opens atarmature 28 the circuit of line relay 116 of repeater D in the No. 2exchange. Upon deenergizing, the line relay 1.16 opens at armature 137the circuit of line relay 258 of repeater D, and at armature 130 closesthe circuit of slow acting relay 118 and opens the circuit of releaserelay 117. Upon deenergizing, release relay 11? opens at armature 138the circuit of slow acting relay 118, and removes ground from releasetrunk conductor 164 thereby allowing relays 115 and 112 to deenergize.Relay 115, upon deenergizing, removes the busy potential from releasetrunk conductor 161. Relay 112 upon deenergizing opens at armature 126the circuit of cut off relay 102. Relay 102 accordingly deenand opens atarmature 104 the circuit of visual. signal 106 and its multiples, andthe said signals accordingly deenergize. Vfhen ground is removed fromrelease trunk conductor 16 1 relay 238 of repeater D de energizes andthe selectors E and F release in the usual manner. The deenergization ofrelay 238 results in the deenergization of all the relays associatedwith repeater D and jack J that have been'energized during theconnection. Line relay 258 the circuit of which was opened by thedeenergization of line relay116 of repeater D, upon deenergizing opensat armature 259 thecircuit of line relay 303 of repeater D Line relay303 upon deenergizing, opens the bridge across conductors 30 1 and 305.When this is done the circuit of the line relay of the connector towhich the connection has been extended is broken and the connector is released in the usual manner. The release relay 307 of the repeater Dfalls back about the same time as the release relay of the ronnector andthe two of them remove ground from release trunk conductor 306 therebyreleasing the intervening selectors. The connection is now completelyreleased and all the apparatus used is restored to common use.

We shall now assume that the subscriber at substation A desires to callthe subscriber at substation A, Fig. 6, in exchange No. 2, whose numberis 9110, the method of procedure in this case in calling the tollrecording operator eing as hereinbefore described. We shall assumefurther that when the toll operator in exchange No. 1 starts toestablish the connection to the subscriber at substation A she findsthat the trunk line X is idle and accordingly inserts the plug oi anidle cord circuit, the cord circuit O, for example, into the associatedjack J Obviously when this is done the same circuit operations takeplace as took place in the previous call when the said operator insertedthe same plug into the same jack. In this case as before the visualsignal 34 and its multiples in front of the other operatorsareenergized, and repeating relay 27 is en ergized and closes thecircuit of the line.

relay. 11.6 of repeater D. The final resultis that the selector E 18-made ready for operat onin theusual manner and ground is ed upon releasetrunk conductor 161 of repeater D. The operator nowinserts the plug ofthe dial cord P into the acl; J thereby including the calling device Sin the circuit of repeating relay 2?.

The operator may now operate her calling device in accordancewit'h thefirst digit 9 of the desired number. Thereupon, the selector Er lees itsshaft and wipers step by step until the l'atter stand opposite the ninthlevel otlh'ank contacts an'd rotates them to pick out an idl'eftrunkline; "VVeshall assun'ie that the trunk line terminating in the contacts200, 201 and .202 is the first one found idle and consequently the oneselected. The conductors extending fron these bani: contacts areunderstood to extendto and terminate in a second selector switch such asthe selector F, Fig.6. The line and release relays of the said selectoraccordingly energize preparing the switch for. operation in the usualman ner.

I In the repeater D, as a result of calling the first digit the'arniatures 125 and 128 of relay 112 are operated to close thereat twopoints in the talking circuit as outlined by the heavy conductors, thecut oil relay ssociatedfwith the jack J" is operated with the resultthat the upper winding of relay 100 is reinoved from in 'bridgeot thecon duc'tors leading to jack J and the visua signal 106 together withits multiples in front of the other operators is energized to iniorintheoperators in exchange N0. 2 that the trunk line X is in use.

The operator in exchange No, 1 may now manipulate her calling device Sin accord ance with the remaining digits of thedesired number whereuponthe second selector to ivliichthe connection has 'be-neXtended and aconnectorswitch "such as the connector l li Fig. 6; are operated to giveaccess to the called line. Thereinainder of't'he operation being old,need not be explained.

\Ve shall assume that some subscriber in exchange No. '2 desires to callthe subscriber at substation A in exchange No. 1. In order to initiatesuch a, call the 'subscriberin exchange No. 2 reinoves his receiver anddials the digit 0 thereby causing a first selector such as the selectorE, Fig. 6, to

raise its wipers to the tenth level and rotate them to pick out an idletrunk line leading tothe toll recoi-ding operator. Since the callingofthe toll recording operator has nothing in particular to do with thepresent invention it will notfb'e necessary to describe this in detail.It Will siu'iice to say that when the toll recording operator answersidle cord circuit, the cord circuit O for e20 ainple, into the jackassociated with an idle trunk line such as the aclr J associated withthe trunk line X. Assuming that it is the jack J*, the cut oti relay 102is operated in series with sleeve relay 107. Upone-nergizing, cutolirelay/102 opensthe circuit'of the upper Winding of relay 100 at armature103., and at armature 104' and its working contact operates the visualsignal 106 and its nrultip-lesin front of the other operators. A branchof the energizing circuit for visua signal 106 extends by way ofarinature 1 3 and its resting contact, and resting contact of armature166 and said armature to battery'throu h relay 113. clay 113, upon energizing, p aces ground on release trunk conductor 161 at arn'iature131, thereby making the repeater l) busy to the selectors which peatingcoil T. This latter operation, however, has no particular utility inthis case, since the exchange No 1 is a nianual change, but is done inorder that repeaters such as repeaters D and D may be interchangeable,and also that repeaters in exchange No, 2 will not need to be changed incasethe No. 1 exchange is later cut over to automatic operation; Thedial jackd is associated With the repeater for the reason.

Theoperat-or now operates key K in such a direction as toprojectgeneratorout on the trunk line X thereby op rating relayassociated with jack J Relay 39, upon energizing, closes a lockingcircuit for itself and an energizing circuit for lainp L and cordcircuit 0 for example, into the jack J whercuponthc cut oi'l' relay 35is energized in series with relay 10 in the usual manner.

Upon energizing, cut oii relay 35 unlocks the relay 39 at armature 37thus extinguishing the line lamp L and at armature 37 closes anothercircuit for the visual signal 3 1 and its multiples. The toll operatorin exchange No. 1 now learns from the toll operator in exchange No. 2the number of the called subscriber and thereupon completes theconnection by way of the other plug of the cord circuit in use andsignalsthe called subscriber.

When the called subscriber answers he can converse with the tolloperator in exchange No. 2. She tells him to wait on the line while shecalls the subscriber that desires connection with him. The operator theninserts the other plug of cord circuit 0 into the jack J, the said jackbeing associated, on the toll board, with the jacks J and J but is shownat some distance away so as to be able to sh w the cord circuit fully.The same is true for the other jacks similarly located. When the plug isinserted into the jack J ground through the low wound sleeve relay 110and the sleeve of the cord is sup-- plied to release trunk conductor16 1. Belay 115 immediately energizes and at armature 1S5 shifts thecircuit of release trunk conductor 161 so as to include the workingcontact of armature 135 instead of its resting contact, and armature 131and its working contact. The low wound relay 110 upon energizing opensat armature 111 a point in the circuit of lamp L The polarized relay 159in the cord circuit O is included in bridge across conductors 161 and165 the said bridge including the heavy talking conductors and the righthand winding of the repeating coil. The two relays, supervisory relay159 of cord circuit 0 and line relay 175 of the repeater E, energize inseries, the current flow in relay 159 at this time being in such adirection as to operate the said relay. Upon energizing, polarized relay159 closes a point in the circuit of the super visory lamp The linerelay 175 of selector E, upon energizing closes the circuit for releaserelay 176, which upon energizing, prepares the switch for operation inthe usual manner and at armature 18st places ground on release trunkconductor 16stE there by shunting relay 110' in the cord circuit 0.Relay 110 accordingly deenergizes and lights the supervisory lamp L Theoperator now throws her key K thereby removing the polarized relay 159and the associated windings of the repeating coil from the bridge acrossconductors 163 and 165 and substituting the calling device S therefor.Relay 159 accordingly d-eenergizes and extinguishes the lamp Theoperator may now operate her calling device S in accordance with thedigits of the desired number whereupon a first and second selector and aconnector, such as the connector H, Fig. 6, are operated in the usualmanner to give access to the calling line.

After the operator has finish-ed dialling the number she restores thekey K to normal thereby reinserting the polarized relay 159 into thebefore mentioned bridge across conductors 163 and 165, whereupon, thesaid relay operates its armature to relight the supervisory lamp L Whenthe calling subscriber answers, the connector switch operates to reversethe current flow conversation is finished they replace their receivers.When the receiver is replaced at substation A the supervisory lamp L isf ted in the usual manner. hen the receiver is replaced at thesubstation of the subscriber in exchange No. 2, the connector switchreverses the current flow in conductors 163 and 165 back to normal,thereby reoperating the polarized relay 159 and relighting thesupervisory lamp L The operator in exchange No. 2 upon perceiving thedisconnect signal removes the plug from jack J, thereby releasing theautomatic switches in the usual manner, and operates her ringing key toproject ringing current out over the toll line X and then removes theplug from jack J". In response to the ringing current sent out over thesaid toll line, relay 29 in the cord circuit 0 is. energized and atarmature 3O closes a locking circuit "for itself and an energizingcircuit for supervisory lamp L by way of the resting contact ofspring 33and the said spring and the armature and contact of relay 10. Theoperator in exchange No. 1, upon seeing the lighted condition of thelamps L and L, pulls down the connection. The apparatus is now allrestored to normal.

We shall now assume that the toll operator in exchange No. 2 receives aticket call-' ing for a connection between some subscriber in the saidexchange and a subscriber in the No. 3 exchange. Upon the receipt of thesaid ticket the operator inserts the plug of an idle cord circuit, theleft hand or outgoing plug or" the cord circuit 0 for example, into thejack associated with an idle trunk line, such as jack J associated withthe trunk line Z. leading to the LTD. 3 exchange. lVhen the plug isinserted into the said yacl: the cut oil relay 2 18 is energized in theusual manner and closes at armature 251 a circuit for the visual signal247. A

' branch of the energizing circuit for the visduct-or ual signal extendsby way of armature 24-2 and its resting contact. resting contact ofarmature 267 and said arn'iaturo, and relay 266 to battery. Relay 266,upon encrgizing places ground on release trunk coni at armature and atarmature 26a places battery on the trunlr line Z by way ot the followingcircuit: from battery through resistance R resting contact of armature24-6 and said ari'nature, working contact'ot armature 261 and saidarmature, resting contact of armature 239 and said armature, conductor260 and the upper and lower right windings of repeating coil T Theplacing of battery on the trunk line Z operates the line relay of therepeater D on the other. end of the said trunk line has beenhereinbetore described. The line relay of the said repeater energizeswith the .iinal result that the said repeater is made busy to theautomatic switches in the No. 3

exchange, andthe selector switch associated with the said repeaterina-de ready for operation in the usual manner.

The operator now inserts the plug of the dial cord into the jack J",whereupon relay 25S is operated over the "following circuit: 'fromground by way of the ring contact of jack J", the ring of the plug ofthe "dial cord P, calling device 5, tip ot the As soon the callingdevice said plug; ring contact of the said jack, resting contactoif'armature 26a.- and said armature, resting contact ot armature 240and said armature. and the upper winding of line relay258 to battery.Line relay upon energizing, closes a multiple p int in the circuit frombattery through resistance R to thetrunlr line Z. The operator nowoperates the calling device S in accordance with the first digit ctthedesired number. S is moved from normal position, spring 145 inalzescontact with its working contact thereby clo ing the following; circuit:from ground by way of spring 14-5 and its working contact,

the sleeve of the plug of dial cord P sleeve oit jack J armature and itsresting contact,and relay to battery. Relay energizes and remainsenergized until the calling device S is restored to normal position.Relay 24A, upon energizing, opens at armature 2&6 a point in theoriginal circuit whereby battery was placed upon the trunl: line Z thusleaving the said circuit closed only through armature 259 and itsworking" contact. .he calling device S in returning to normal positioninterrupts the circuit of line relay258 a number of timescorrespondsends a corresponding number of impulses to the associatedselector which operates in theusual manner to raise its vipers to thedesired level and rotate them to pick out an idle trunk line terminatingin the said level. As a further result of the calling of the firstdigit, the busy visual associated with repeater D is operated and thetalking conductors are connected up in the same manner in which the sameoperations are performed by the repeater D as here inbefore described.

The operator may now manipulate the calling device S in accordance withthe remaining digits of the desired number there by completing thedesired connection in the usual manner. When the called subscriberanswers the operator tells him to remain on the line while she calls thesubscriber in exchange No. l. The operator now inserts the other plug ofthe cord circuit into the jack J thereby placing ground on release trunkconductor 256 by way of sleeve relay 110. The conductors 255257,inclusive, are understood to extend to and terminate in selector E Fig.6. the banks of which are multipled with the blanks of selector E, Figs.3 and 6. The results in this case are identical with those in the casein which the same plug was inserted into the jack J and consequentlyneed not be described. It will su'ilice to say the calling device S isoperated to complete the connection in the manner hereinbetoredescribed.

When the subscriber in exchange No. 2 answers, the supervisory lamp L isextinguished in the usual manner to give the operator answeringsupervision. The two subscribers may now converse with each other andwhen the conversation is finished they both hang up their receivers.When thesubscriber in exchange No. 2 replaces his receiver thesupervisory lamp becomes lighted. The operator upon noting the lightedcondition of lamp L pulls down the connection. l

When the plug is, removed from cl: J

the automatic switches in the No. 2 exchange released in the usualmanner. lVhen the plug is removed tron i jack i cut off relay 24-8deenergizes and at armatiue 251. opens the circuit of the visual si u24? and its nuiltiples and the said signals ar cordingly deenergire. ASfurther result of the energization of the cut 0H relay 248 the circuitof relay 266 in the repeate D" is broken. Relay 266 upon deenergizing,removes ground troin'release trunk conductor 232 at armature 263, and atarmature 2G1 removes battery trom the trunk line Z. ll heu battery isremoved from the trunk line Z the connection in the No. 3 exchangereleased in a manner hereinbefore described.

We shall now assume that the toll operator in exchange No. 3 receives aticlret calling for connection between a subscriber llfi in exchange No.3 and a subscriber in exchange No. 1. Upon the receipt of the saidticket, the operator in exchange No. 3 inserts a plug" of an idle cordcircuit into the jack J thereby operating the associate-fl cut offrelay, which, upon energizing, closes a circuit for the associatedvisual signal and its multiple: in front of the other ope ators. .Abranch of this circuitextends into the repeater D, causing the saidrepeater to place ground on its associated release trunk conductor andto place battery on the trunk line Z so as to prepare the repeater D inthe No. 2 exchange, and its associated selector switch for operation inthe usual manner.

The operator now inserts the plug of a dial cord similar to dial cord P,Fig. 4.. into the dial jack J and proceeds to call the nun'iber in theusual manner. Upon referring to Fig. 6 it becomes apparent that in ordertoobtain connection with trunk line such as trunk line X leading to theNo. 1 exchan 'e the toll operatorin exchange No. 3 must dial the No. 01.The operator now operatesher calling device in accordance with the digit0 whereupon the selector E Fig. 6, operates in the usual manner to raiseits wipers to the tenth level and rotate them in search of an idle trunkline extending to and terminating in a toll second selector, theselector F, for example. In response to the next digit 1 the selector Fraises its wipers to the first level and rotates them to pick out anidle trunk line. Vi e shall assume in the present case that the trunkline terminating in contacts 228-230, inclusive, is the first one foundidle and consequently the one selected. That being the case theconnect-ion is extended to the repeater D whereupon the usual circuitsare closed with the result that the visual signal 106 is operated andbattery is placed out on the trunk line X, the latter operation,however, hav ing no utility in the present case. The operation ofrepeater D under the same circumstances has been explained hereinbefore,consequently it is not necessary to explain the operation of therepeater D. It will suflice to say that when the cut off relay 102associated with the jack J is energized, in the normal course of events,it opens at armature 103 the circuit of relay 100.

The operator in exchange No. 3 now op- Y crates her ringing key andthereby projects ringing current over the established connection to therepeater D and thence by way of trunk line X to relay 39 in exchangeNo. 1. Relay 39 upon energizing, closes the circuit for line lamp L inthe usual manner thereby attracting the attention of the operator. Theoperator in exchange No. 1 now extends the connection to the desiredsubscriber by means of her cord circuit 0.

When this connection has been completed the toll operator in exchangeNo. 3 inserts the other plug of the cord circuit in use into the jack Jand proceeds to call the subscriber in the No. 3 exchange in the usualmanner. lVhen the said subscriber answers he may converse with thesubscriber in the No. 1 exchange.

hen the conversation is finished the two subscribers replace theirreceivers. the receiver of the subscriber in the No. l e *change isreplaced the usual supervisory signal is given to the operator in theexchange. When the receiver of the sub-- scriber in the No. 3 exchangeis replaced the operator thereat receives the disconnect signal andpulls down the connection but. just before doing so, she projects ringicurrent momentarily out over the coniuc tion to the exchange No. 1thereby operating the relay 29 of the cord circuit 0 and lighting thelamp L in the usual manner. The operator in exchange L D. 1, uponnoting" the lighted condition of lamps L and L pulls down theconnection.

Vi e shall now assume that the operator in exchange No. 3 is required tocomplete a connection between a subscriber in the said exchange and asubscriber in exchange No. 2. The operator accordingly inserts a plug ofan idle cord circuit into a jack. such as the jack J associated with anidle trunk line. When this is done the repeater D is made busy to theautomatic switches in the No. 3 exchange in the usual manner and batteryis placed out on the trunk line Z thereby making the repeater D inexchange N0. 2 and its associated selector switch ready for operation inthe manner hereinbet'ore described. The operator in exchange No. 3 nowoperates her calling device in accordance with the number of the.desired subscriber whereupon a first and a second selector and aconnector switch in the No. 2 exchange are operated to give access tothe called subscribers line.

The operator completes the connection to the subscriber in exchange No.3, in a manner hereinbefore described, whereupon the two subscribers mayconverse with each other. \Vhen the conversation is finished the twosubscribers replace their receivers. The replacing of the receiver ofthe subscriber in exchange No. 3 brings in the usual disconnect signal.The operator, upon perceiving the disconnect signal, pulls down theconnection. lVhen the plug is removed from the jack J the circuitconditions of the repeaters D and D are restored to normal and theconnection to the subscriber in exchange No. 2 is accordingly released.When the plug is removed from the jack J the connection to thesubscriber in exchange No. 3 is released in the usual manner.

Referring now to Fig. 2, a point in conill) . scriber in exchan e N0. 3,by way of the right'hand end or cord circuit 0, jack J selector E,selector F, repeater D and trunk line Z, unless special provl ion ismade the supervisory lamp L remains lighted during the entire time thatthe connection is established. In order to overcome this diliiculty, theground which is supplied to release trunk conductor 16%, by the cordcircuit 'O, isledthrough the sleeve relay 110, the said relay beingnormally short circuited by ground placed on the said release trunkconductor by the release relay of a selector or connector switch.However, when a connection is extended to a repeater such as therepeater D the relay 110 is not short circuited, because the repeaterdoes not ground the release trunk, and, because itmust supply ground tohold tour relays energized one in each repeater and one in each of theselectors, the said relay 110 accordingly energizes. Relay 110 uponenergizing opens a point in the circuit of supervisory lamp Li'therebyextinguishing the said lamp. 7

In the connections hereinbetore described all excepting the two callsincoming to on change No; 1 from exchanges Nos. 2 and 3,

respectively, are completed automatically by the toll operator in theexchange in which the call originates without the aid of an interveningoperator. It so desired, howi ever, any of the connections hereinbeioredescribed may be set up by the cooperation of two or more operators.This is obviously true in view of the fact that regardless of therepeaters such as D, D and D the toll lines are connected totheirassociated jacks at the operators position in the same 111111- noras they would be were the exchanges No. 2 and No. 3 manual instead ofautomatic. That is,,while adding the automatic featuresto theinter-exchange toll trunks all the manual operating features have beenre tained, For example, if the toll operator in exchange No. 1 desiresto extend a con nection to some subscriber in exchange No. 2 she mayinsert the plug of an idle cord circuit into the jack such as the jack Jand. operate her ringing key thereby projecting ringing current out onthe trunk line X to cause the ringing responserelay 100 associated withthe jack J to be operated to signal the o 3erator in exchangehlo.litelay 100 upon energizing, closes a locking circuit for itself and anenergizing circuit for lamp L A branch of this circuit e2:- tends by wayof the resting contact of armaturetlO andthe said armature to the visualas follows A branch visual sigsignal 106 and its multiples. the saidsignals are energized. of the energizing circuit for nal 106 extends byway of armature 12c and its resting contactQthe resting contact ofarmature 166 and said armature, and relay 113 to battery. Uponenergizing, relay 113 opens the circuit of line relay 116 at armature129. llpon deenergizing, line relay 116 opens the control circuit ofselector 111 whereupon the line and release relays of the said selectordeenergize. il hen the op-' erator in exchange No. 2 answers, theinserting of the plug into jack J causes the ringing response relay 100to be disconnected from in bridge of the conductors leading to the saidjack, thereby extinguishing the associated lamp signal. The operator inexchange No. 1 now requests the operator in exchange No. 2 to completethe desired con nection. The latter operator does this by inserting theother plug of the cord circuit in use into the jack J after which shethrows the proper key and operates her calling device in the usual toextend the connection to the desired subscriber.

.Sin'iilarly the toll operator in exchange No. 2 may signal the operatorin exchange no. 3 and request the latter to complete a connection toanother subscriber in the said I exchange. The same is also true in casethe toll operator in exchange No. 3 wishes the toll operator in exchangeNo. 2 to complete a connection to a local subscriber. riot only can thecall intended for a subscriber in an adjoining exchange be trunlredthrough an intervening operator but also a call from the first exchangeto the third exchange and vice versa can be completed with the aid oi:one, or more interveningoprators. l or example a call from exchange No.1 tea subscriber in exchange l lo. 3 may be handled The toll operator inexchange No. 1 may signal the operator in exchan N0. 2 and request thelatter to complete ternate inethocs either oi which may be usedby theopera; r in exchange 2 in extending nnection to a trunk line such as thetrunh line X. or Z, when completing calls that are to be trunlredthrough the lflo. exchange; Upon the receipt oi such a call, theoperator may insert a plug in the jack such as the jack T u or Jdepending upon whether the call is coming from the li o. 1. or the No.3exchange; and operate her calling device to obtain connection with E lia trunk line to either exchange No. 3 or exchange No. 1.

The alternate method of handling such a call is to provide the operatorin exchange No. 2 with an additional set of cord circuits. like the oneshown in Fig. 7, which differs form the cord circuit C in that the twoends are identical with each other and with the l ft hand or outgoingend of cord circuit O. Ti e shall term this group through switching cordcircuits. In case an operator, who is supplied with both .lrinds of cordcircuits, receives a call that is to be trunked to a third exchange shemay, in case she so desires, remove the plug of the cord circuit used inanswering the call, from the jaclr J or 5 depending upon from where thecall is coming, and insert a plug of one of the through switching cordcircuits in its place. The other plug of this through switching cordcircuit is inserted into the proper jack. From this point the call mayproceed automatically or manually as desired. This method of handlingthrough calls is substantially the same as is employed in systems inwhich all toll calls are handled manually.

Having fully described and ascertained the features of this invention,what is considered to be new and desired to have protected by LettersPatent will be pointed out in the appended claims.

lVhat I claim as my invention is:

1. In a telephone system, a repeater, an automatic switch having a linerelay, a trunk line extending" through said repeater and terminating insaid switch, there being a normally open connection in each talkingconductor of said trunk line at said repeater, means for transmitting animpulse of current over the trunk line, a line relay in the saidrepeater responsive thereto for transmitting an impulse to the linerelay of said switch, and means in the repeater for closing saidconnections to establish a through talk ing circuit only after theswitch has operated.

2. In a telephone system, a r peater. an automatic switch, a trunk lineextending through said repeater and terminating in said switch, therebeing a normally open connection in each talking conductor of said trunkline at said repeater, means for transmitting a series of currentimpulses over the trunk line to said repeater, means in the repeater forrepeating said series of impulses over said trunk to said switch, andcontacts in said repeater operated responsive to the reception of one ormore of the im pulses of said series for closing? said connections.

In a telephone system, a repeater. an automatic switch, a trunk lineextending through said repeater and terminating in said switch, therebeing a normally open connection in each talking conductor of said trunkline at said repeater whereby said trunk line is divided into incomingand outgoing sections at the repeater, means for transmitting a seriesof current impulses to said repeater over the talking" conductors of theincoming section of said trunk line in parallel, means in said repeaterfor transmitting impulses to said switch over the talking conductors ofthe outgoing section of said trunk line in series, and a relay in saidrepeater operated responsive to the res connection in each talkingconductor of said trunir line at said repeater, whereby said trunk lineis divided into incoi'nin p and outgoing sections at the repeater, abranch extending from the incoming section of the vice connected inbridge otthe'tallring conductors of said branch, means for transmit tingimpulses overthe incoming section of said trunk line to said repeater,therepester being responsive thereto to transmit impulses over theoutgoing section to said switch, relay contacts in said repeateroperatcd responsive to the reception of one or more impuls s for closingsaid connections, and other relay contacts also operated responsive tothe reception of one or more impulses for disconnecting said signalingdevice from the bridge of said branch.

5. A combination automatic and manual toll trunking system comprisingtwo ex changes and an interconnecting toll line, a repeater and anautomatic switch individual thereto in the second exchange, the saidtoll line normally terminating in said repeater, means in the firstexchange for generating impulses to operate said repeater and therebyoperate said switch, there being means in the repeater fortelephonically connecting the conductors of the toll line through tosaid switch, manual. apparatus at the second exchange including plug'and jack equipment optionally employed to establish a con nection aroundsaid repeater from the toll line to said switch, and means in the secondexchange associated with said manual ap paratus for generating impulsesto operate said switch.

6. In a telephone system, a trunk line eX- tending through an automaticrepeater and transmitted over the trunk line and relayed atsaidrepeater, and means for controlling ti unh line to a manual jack,a'signallingj" at:

dividual to said toll line, an operators posi tion in each exchange,branches of said toll line extending to jacks at said operatorspositions, means whereby either operator can establish a control circuitfor said switch over the branch extending to her position, and callingdevices at the operators posi tions for interrupting the controlcircuits to direct the movement of said switch.

9. In a telephone system, a toll line connecting two exchanges, anautomatic switch in the first exchange associated with and individualtosaid toll line, an operators position in each exchange, branches of saidtoll hne extending to 121CkS at said operators positions, means wherebythe operator at the first exchange can control said switch over twoconductors of said toll line in series, and means wher hy'the operatorat the second exchange can control said switch over two conductors ofsaid toll line in parallel.

10. In a telephone system, a toll line con necting two exchanges, anautomatic switch in the first exchange associated with and individual tosaid toll line, an operators position in each exchange, branches of saidtoll line extending to aclrs at said operators positions, a normallydisconnected toll line extension terminating in said switch, meanswhereby the operator in the. first exchange can control said switch overthe two sides of said extension in series, meanswh-ereby the operator inthe second exchange can control and switch via the two sides or saidtoll line in parallel while the said extension is disconnected, andmeans for connecting the toll line with said extension.

, 11. In a telephone system, two exchanges, an operators position ineach exchange, a trunk line extending from a jack at the operatorsposition in the first exchange to an automatic switch in the secondexchange, there being a repeater inserted in the trunk line thesecondexchange ahead of said EUJVilICl1,'E1 branch xtending from thejack at the operators position at sthe second exchange andcomiectingwith said trunk line at-a point bet seen the said repeater and switch,acalling device the 'operators positio'n. inrthe first'exchan' 'e forcontrolling switch over as by means at saidrepeater, and a callingdevice at the; opera-tors position in the second exchange forcontrolling said switch over said branch: independent oi. aid repeater.

12. in atelephone stem, two exchanges, "l operators position in eachexchange, a trunlr line extending from a jack at the operators positionin the first exchange to an automa .c' switch in the second exchange,there being a repeater inserted in the trunk line at the second exchangeahead of said switch, a branch extending from a jack the operatorsposition at the second exchan e and connecting with said trunk line at apoint between the said repeater and switch,a calling device at theoperators position in the first exchange for controlling said s *itchover the trunk line by means or said repeater, a calling device at31100136 ators position in the second exchange for controlling saidswitch over said branch independent of said repeater, normally opencomiections in the talking conductors of said trunk line at saidrepeater, and means for closing said connections only when the trunkline is in use from the first exchange.

13. In a telephone system, a toll line connecting two exchanges andterminating in manual switchboards in both exchanges, an auton'laticswitch associated with the toll line at the second exchange, a controlcircuit for said switch and means for closing it automatically when thetoll line is taken for use at the first exchange, means whereby theoperator at the first exchange can at her option transmit operatingimpulses over said toll line to control said switch or ringing currentto signal the operator at the second exchange, and means responsive toringing current for automatically opening the control circuit of saidswitch.

145. In a telephone system, a toll line connecting two exchanges andterminating in manual switchboards in both exchanges, an automaticswitch associated with the toll the second exchange, a control circuitline at for said switch and means for closing it automatically when thetoll line is taken for use at the first exchange, means wherebythe-operator at the first exchange can at her option transmit operatingimpulses over said toll line to control said switch or ringing currentto signal the operator at the second exchange, a signalling deviceasso-- ciated with the toll line at the switchboard in the secondexchange and responsive to ringing current, means for disconnecti a saidsignalling device in case the operator at the first exchange transmitsoperating impulses over said toll line, and means for opening saidcontrol circuit in case the said, operator transmits ringing currentover said toll line. i 15. In a telephone system, a trunk line recreatintwo exchanges and ha g hree branches at the second exchange, one branchextending through a repeater to an incomingswitch, a second branchextending to a manual jaclnand the third branch extending to multiplyconnected bank terminals in a plurality of outgoing switches, means forci =iiiiicctiiig with the trunk at the first exchange and for sendingimpulses there over to operate said incoming swi'ch by means of saidrepeater, means for making the trun line busy to said outgoing switcheswhen it is first taken for use, and means operated responsive to the senling oi" impulses over the trunk line for making it busy the said manualjack.

16.111 a telephone system, a tvo way trunk line connecting twoexchanges, three branches of said trunk line at the first exchange, thefirst branch extending through a repeater to an incoming switch, the second extending to a manual jack, and the third branch erLe ding tomultiply con nected bank tern'iinals in a plurality of outgoingswitches, three s' ilar branches at the second exchange, means foroperating one of said outgoing switches at the first exchange to connectwith said trunk line via the third branch thereof, means "for thentransmitting current impulses over the trunk line to operate theincoming switch at the second exchange means oi the associated repeater,means for at once making busy the second branch oi. said trunk line atthe first exchange as soon as the trunk line is connected with, andmeans for making busy the second branch at the second exchange also, thesaid last busying means being etifectii'o only attcr one or moreimpulses have been transmitted over the trunk line.

17. In a telephone system, a two way trunk line connecting twoexchanges, three branches of said trunk line at the first ex change, thefirst branch extending through a repeater to an incoming switch, thesecond extending to a manual jack, and the third branch extending tomultiply connected bank terminals in a plurality of outgoing switches,three similar branches at the second exchange, means for operating oneof said outgoing switches atthe first exchange to con nect with saidtrunk line via the third branch thereof, means for then transmittingcurrent impulses over the trunk line to operate the incoming switch atthe second exchange by means of the associated repeater, means forestablishing busy conditions at the second branch in the first exchangeand at the third branch in the second exchange before any impulses aretransmitted over said trunk line, and means for establishing a busycondition at the'second branch in the second exchange, said last busyingmeans beingeitective only after one or more impulses have beentransmitted.

18. A combination toll and local trunking system comprising a pluralityof automatic exchanges interconnected by toll lines, local firstselectors, second selectors, and connectors in each exchange for settingup local connections, a toll repeater included in each toll line at eachexchange, a toll first selector associated with each toll repeater, and"nultiplo connections between the banks of he toll first selectors andthe local first seectors in each exchange, whereby the local econdselectors in each exchange are made accessible to both toll and localfirst selectors.

19. in a telephone system, lines, a link circuit, a supervisory signalassociated there with, means including a trunk line for extending aconnection from said link circuit to a called one of said lines, meanscontrolled by the response of the subscriber on said called line foroperating said signal, means including said trunk line for extending aconnection from said link circuit to another called one of said lines,the last named connection being without means to operate said signalwhen the subscriber said other line answers, and discriminating meansassociated with said link circuit for operating said supervisory signalautomatically when the last named connection is set up.

20. In a telephone system, an operators cord circuit, means includingsaid cord circuit for setting up a connection .to a called line by wayof a local trunk line, means including said cord circuit for setting upa connection to another called line by way ofa toll line, a second localtrunk line included in both connections, a supervisory signal associatedwith said cord circuit, a circuit for said signal, means tor controllingsaid signal over said circuit responsive to the answering of thesubscriber on the first named called line, and means for altering saidcircuit to control said signal responsive to the extension of the lastnamedconnection to said toll line.

in a telephone system, a trunk line terminating in an automatic switchand having normally open contacts in the talking conductors, meansresponsive to a series of digit impulses received over the trunk linefor repeating suchimpulses past said open cont cts to set said switch,and means for clo said open contacts responsive to the impulse of saidseries.

In a. telephone system, a trunk line terminating in an automatic switchand having normally open contacts in the talking conductors, meansresponsive to a series of digit impulses received over the trunk linefor repeating such impulses past said open contacts to set said switch,a slow acting relay heldenergized responsive ,to said "series ofimpulses, a second relay for closing said

